1. Field of the Invention
This invention relates to fire retardant materials, and more particularly to fire retardant thermal and acoustic insulation materials.
2. Description of the Prior Art
The term "non-woven textile clipping pad" refers to a relatively thin, highly flexible pad material fabricated from recycled scrap fabric and carpet remnants used for applications such as mattress pads, furniture pads and carpet pads. This material can be described as an open weave, air permeable fiber pad formed from a plurality of compressed, interlocked fiber strands having a generally uniform thickness with non-uniform first and second side surfaces which are defined by a plurality of exposed, interlocked strands.
A layer of aluminum foil or an aluminized polyester sheet can be bonded to one or both sides of the fiber pad material to create a product which reflects heat and high frequency sound and has the capability of absorbing or attenuating low frequency sounds. The aluminum layers enhance the heat reflective and heat insulating properties of the fiber pad material rendering it potentially useful for automotive or aircraft sound reduction and heat insulating applications.
The pad material is fabricated from a wide variety of chopped, slashed, recycled scrap including cotton and cotton/polyester fabrics where the length of the resulting chopped fiber strands as well as the material composition and individual strand diameter results in a flexible, relatively strong pad material but with a highly non-homogeneous, non-uniform composition.
In an effort to meet the fire retardancy standards mandated by the Federal Aviation Administration (FAA) for use in private and commercial aircraft, by the U.S. Coast Guard for use in private and commercial water craft and by the Department of Transportation for use in private and commercial vehicles and by various local and federal agencies for use in the construction of homes and commercial buildings, attempts have been made to render this highly flammable pad material both flame and fire retardant.
A commercially available liquid fire retardant sold under the trademark AMSPERSE FR-21 has been coated onto the exterior surface of this pad material and has been injected into the pad material in an effort to enhance the fire resistance characteristics of the flammable pad material. Because the pad includes widely varying percentages of recycled nylon, rayon, cotton, polyester and related materials and because the length and diameter of the various fiber strands vary widely, the addition of liquid AMSPERSE fire retardant chemical to the pad material somewhat reduced its flammability but the pad material still burns and emits smoke, but at a slower rate than for untreated pad material. Even though consistent amounts of the chemical flame retardant was added to the pad material during its manufacture, inconsistent test results were obtained during the course of burn testing due to the non-homogeneous, widely varying nature of the recycled fiber materials and wide variations in the relative ratios of different categories of recycled fiber input materials.
Requests to supply pad compositions having a more uniform fiber content were rejected by the pad manufacturers as economically impractical as a result of the requirement that all of the randomly varying recyclable input materials be utilized. While treatment of the pad material with chemical flame retardants somewhat reduced its flammability, some, but not nearly all, fire retardant standards could be met by pad material treated with AMSPERSE fire retardant.
After lengthy research and development efforts, and although aluminum foil coated pad materials yielded highly advantageous thermal and acoustic insulation properties, non-woven textile clipping pad could not be modified to achieve a high level of resistance to fire and flame.